Cable or sling



Feb. 26, 1929. A 1,703,269

J. MGC. GARRIS CABLE 0R s'LING Filed March 19, 192'?v v 5 Sheets-Sheet 2 In/vento@ Feb. 26, 1929.

J. MCC. GARRIS CABLE OR SLING Filed March 19, 1927 3 Sheets-Shet 3 gennanten,

61H01 um,

Patented Feb. 26, 19129.

UNITED STATES JOISEPH MCGLINTOCK GARRIS, Fy AVALON, PENNSYLVANIA.

CABLE OR SLING.

pplication led March 19, 1927. Serial'No. 176,714.

This invention relates generally to cables, and while it is herein illustrated and de- -scribed as a sling of the character usually employed in lifting and handling heavy structures, a general application of the principles embodied inthe invention is contemplated within the scope ofthe appended claims.

S0 called slings by reason of their use are always subjected to severe tensionand strain,

i0 and all cable used for such purposes has been found tobe objectionable for its insufficient flexibility, which prohibits it from 'readily conforming or adapting itself to the contour of the object to be lifted or handled. More important than this however, is the objectionable inherent friction and shearing action presented by the' adjacent surfaces of the respective units of which the cable is composed,

. where said units intersect or cross each other.

` This obviously short'ens the life the cable or sling. y

In addition to this, Vall of which is the direct result ofthe manner in which the units of the cable areassociated `in the finished 25. product,l it is afwell known fact that when` a sling or cable is used for lifting heavy structures, all the units of the cable are not subjected to equal shares of the total weight or load. Consequently the maximum strength of a cable or sling of a given size or weight is never obtained.

It is'therefore, the object of the present invention to provide a cable capable of handling and sustaining heavy strains with a minimum of internal wear and friction, coupled With a maximum degree of flexibility, which com? bination not only produces a cable less liable to break under heavy loads, making it admirably advantageous for use as a sling, but which also contributes to the life of the cable.

One of the chief characteristics of the present invention resides'in the provision-of a cable, wherein the respective units of which it is composedare spirally interwoven'in a` such an angle, that the strands of which the and leave each other at their points of interrespective units are composed, approach and leave each other approximately in parallelism at theirpoints of impingement, and also lie approximately parallel with the longitudinal center of the cable itself, thereby present sliding and gripping, rather than shearing or cutting surfaces to each other.

More specifically stated, it is my purpose to produce a cable made up of aplurality of oppositely twisted units, equally divided into what is termed right hand lays and left hand lays, each unit having a predetermined spiral l path or pitch, so that as the opposed units are' spirally interwoven, by passing over and under alternately, the said units intersect at natural and proper angles t0 maintain the strands of said units parallel with each other, and also parallel with the longitudinl axis of the -cable itself.

The invention further contemplates a newA and unique method of producing a cable embodying the foregoing desired characteristics, f and essentially consists in what is termed preforming' the right and left hand lay units, with a predetermined spiral pitch, to relieve. said units of all distortional Strain when they are untwisted and spirally interwoven into the nished product, and which preformation of said units permit the latter to approach S5 section, with the strands of the respectiveunits lying 'in parallelism with each otherA and with the cable itself, or substantially so. I

An important yfeature of the cable formed by my new and ,improved method, resides in the fact that the tensile strength of each unit and its component parts is -fully developed under a .strain or load, s o that the latter is equally distributed over the various units, thereby materially enhancing the safety value of the cable for heavy work, and also prolonging the life of the same.

Another important characteristic. of a cable constructed in accordance with my invention, resides in the fact that as each preformed unit is untwisted while being spirally wound into the finished product, the original lay of veach unit is preserved, thereby causing the opposed units to co-act under tension to develop the maximum tensile strength ofthe cable, and to also revert .to their normal positions when the strain is relieved, in which manner the original high degree of flexibility of the cable is maintained throughout the life of the no Before'enterin into a detail description of the invention as i ustrated in the accompanyingdrawings, I wish to have it understood that the terms' right hand lay and left hand lay as used throughout the specification and claimshave reference to the direction in which the strands themselves of which 'each unit is composed are twisted, while the ,terms or expressions right hand twist7 and e production of connecting the'free 'ends of the unit.

Figure 2' is a similanyiew showing both ends of the unit looped.

Figure 3 is a view showing how the units are arranged before they are spirally inter- Jwoven into the finished product.

Figure 4 is a view showing two groups of elements ready to Vbe spirally interwoven into a cable or sling` Figure 5 is a view showing .the units partly interwoven to illustrate how the units are brought together to accomplish the foregoing I obJects.

Figure 6 is a view similar to Figure 5'- showing the ccnstru'ction of a cable without a core.

Figure I is a view of a sling constructed in accordance with the invention. i,

Figure 8 is an enlarged fragmentary view Y of a cableembodying the principles of the invention.

As hereinabove pointed out, a cable constructed in accordance with the principles embodied in this invention, essentially makes use of an equal number ofright and left hand lay units, and while these principles may be embodied 'in cables for general use, they will be hereinafter specifically/described in connection with a sling, constituting one embodimentof the invent'in. 4

Each ofthe units of which the sling is composed, consistsof a single length of rope,l

which may vary in lengthwithout departing from the inventive idea, and adapted to be 'folded upon itself,and.l1ave its free endsy sultably spl-iced .to make itl endless. These units are vdivided or otherwise joined together intogroups of equal numbers, ohegroup being `distinguished from thel other group in the particular lay ofthe strands of which each unit is composed. It might here lbe stated that any equal number of units may be used to form acable of any desired diameter, depending of course upon the strength and rior to their as-L manner to provide la sling formed by the 'folding of the units in` flexibility desired, and the particular urpose for which the cable is to be used. Y or instance, I have illustrated in F ieure 4 two groups of these units, one group being indi- \cated at A and the other group being indicated at B, each groupfor the purpose of illustration including two of said units. It will be observed that the strands of which the units are composed, forming group A are twisted to-I the right, and commonly known as right hand lay units; while the strands of which the units are composed, included in group B are twisted to the left, and are termed left hand lay units.K The units of group A, or otherwise termed right hand lay uints are indicated at 10, while the left hand i `la units of group B are indicated atf11. T e units of each group are spirally interwoven at ,a point betweenl their ends as at 12, and folded as illustrated in Figure 4, after which the yrespective groups are arranged side by sideand further interwoven spirally to complete the sling. On the 'other hand `these units may be arranged side by side as illustrated in Figure 3 and then folded at a point between their ends, and the units of the different groups alternately passed over and under each other in the formation of the sling.Y When the units are thus folded upon themselves they are spirally interwoven in 'a oop at one end of the the manner just described, while the free ends ofthe units are formed'with loops which when the cable or sling is finished, lie' side by side, so that the loops can be associated with a thimble or eye 13, ofwellknown construction, and in any ordinary well known manner. Whencompleted the slingwill be similar to the article indicated at 14 in Figure 7 It is,essentially important that each unit ofthe sling be initially preformed, in order to provide 'an article which is subjected to av y minlmum of internal wear and friction, when subjected to heavy strains or lifts, and at the same time possess a maximum degree of flexibility, which is particularly advantageous in slings, permitting the latter to readily accommodate itself to the shape or contour of the object ,to be handled. Therefore,

each unit is initially twisted as shown in Figure 1, and the unit is twisted in a direction opposite the lay of the strands of which the unit is composed. For instance cvery'right hand lay unit is initially twisted to the left, and/every left hand lay unit initially twisted to the right. IThis prcformation of the units relieve the latter of any and all distortion, so" that when they are incorporated into the cable or sling, the strands of, the respective units lie parallel with the longitudinal axis v of the finishedl product, and present rela tively sliding surfaces to each other at their points of intersection, in contradistinction to the. construction of cables and slings in present dayuse, wherein the respective units present a chaiing and shearing action at their points or intersection. It is of course understood that as these preformed units are being spirally interwoven with each other, they are untwisted as clearly illustrated in Figure 4E, which is done to preserve the original la)7 of the respective units, thereby causing the opposed left and right hand lay units to co-act under tension and develop the maximum tensile strength of the product. It is by reason of this unique construction and arrangement, that when the cable or sling is subjected to heavy strains and loads, each and every unit of the article sustains its proportionate amount of the load, and inasmuch as the latter is equally distributed over the component parts, both the safety value and ,life of the cable is materially enhanced. It will be observed upon inspection of Figure that as each unit is passed.

over orA under the adjacentunits, while being spirally interwoven into a cable, the particular unit is partly untwisted for the purvposes above mentioned, and that the. strands of the respective units approach and leave each other in parallelism at their points of intersection, and also lie parallel with the longitudinal axis of the cable itself. This fact alone not only contributes to the free relatively sliding movements of the respective units, as they seek a common center under the strain of a load, but also provides a cable with a comparatively smooth exterior capable of being slipped or slid about objects to be lifted with little possibility of the strands being cut or caught by sharp corners or projections on said objects. Equally important, however, is the fact that a cable constructed in the manner just ldescribed affords the product a relatively high degree of flexibility, in thatfthe component parts immediately revert to their normal positions when relieved of strain, and in this manner the desii-ed flexibility of the sling is maintained throughout the entire life of the latter.

In Figure 8 I have illustrated an enlarged fragmentary view of a cable constructed in accordance with the invention, and wherein 15 represents a core of relatively soft material about which the units are spirally inter-v woven, as contradistmgutshed 'from cables which are plalted or braided. and inasmuch as the units of the cable are capable. of relative sliding movement parallel withthe axis of the cable. the relatively soft core 15 serves as a cushion for these units as they seek a common centerunder strain, and also assists in minimizing internal friction. It is of course to be borne in mind that thecore 15 is only used withL cables orslings of particular sizes, and that the principles of the present invention may also be embodied in a sling without the 'use of the core, such as illustrated in Figure 6. Irrespective of this, however, the

manner of preforming right and left hand'lay units, and spirally intel-weaving the same 1n the manner above described results .1n a prod` uct where the strands of the respective units f lie parallel with each other and parallel with the axis of the cable as clearly illustrated in Figure 8.

' In accordance with my improved method of constructing acable or sling, while I make use of endless units as hereinabove men(- fact permits the cableto -be formed from a plurality of units all of equal lengths, and when the units are spirally interwoven together, the loops 16 will all lie side byv side, in the same plane, so that they can be associated with the thimble or eye 13 without any'difliculty. After each unit has been so preformed the free ends of each unit are then joined together in any suitable manner to form a loop 16, and the units are then arranged side by side as hereinabove set forth to form a .component part of: the cable or sling.4 Another important feature of the preformation off these units resides in the fact that by so doing each unit is given a predetermined spiral pitch, which is determined or governed by the length of the unit, and consequently when the various groups Aof units are being yspirally interwoven together, each unit as it is untwisted to preserve its original lay falls into a natural position with the'other units, allowing the strands of the component unitsto approach and leave eachother in parallel lines at their points of intersection.

While it is believed that from the foregoing description the nature and advantages of the invention will be readily apparent, I desire to have it understood that I do not limit i myself to anything shown or described, and that I reserve the right to make such changes and alterations in the /construction and arrangement of parts, as fallwithinvthe scope of what is claimed.

IVhat is claimed is:

1. A new and improved method of con'- strueting cable, consisting in theuse of a plurality of units equally divided into groups of each unit in an opposite direction to its lay, to relieve said unit of distortion, and give said unit a predetermined spiral pitch, and then alternately untwisting said units of the respective groups as they are being spirally interwoven into a finished product, thereby preserving the original lay of the units and producing a cable of maximum tensile strength and flexibility.

'right and left hand lays, thenpre-twisting 2V. A new and improved method of co'n- 6.' A new'and improved method of con- 65 'structing a cable-sling, consisting in the use of a plurality of single length units, folding each unit between its ends, then pretwisting the unit in a direction opposite the lay of the unit toyrelieve' the latter of distortion, then' splicing or connecting the free ends of the unit together to make it endless, and finally that of its lay to give said unit a predeteruntwistin g the component units while the latter are being spirallyA interwoven in the formation of the sling, and forming eyes by the ends of each unit.

3. A new and improved method of con-, structing a cable sling including a body por: tion and an eye at each end, said method consisting in the use of a plurality of' single length units, equally divided -into groups of right and left hand lays, folding ea'ch unit upon itself at a point between its ends and pretwisting the unit in a direction opposite mined spiral pitch and relieve the unit of distortional strain, then vjoining the free ends of the unit together to make it endless and to form one of said eyes, the eye atk the other `end being formed by the initial folding of said unit, and finallyuntwisting the endless units step-by. Lstep as each is spirally interwoven into the finished product.

4. As a new and improved method of ,forming a: cable sling consisting in the use of a plurality of single length units equally divided into groups of right and left hand lays, foldingeach unit upon itself at a point between its4 ends and then pretwisting the unit in a direction opposite its lay, giving the unit a'predetermined spiral pitch, and forming a loop at one end of the unit, then A joining the free ends of the unit together in the formationof a loop .at the other end of the unit, then laying the units side by side and folding all of said units upon them-k selves, then untwisting said units individuallyas they are spirally interwoven into a finished product, and in a manner to form a loop at one end thereof and bringing all of v the first mentioned loops side by side, in the same plane, and finally providing said loops with a thimble at each end of the sling.

5. Anew and 'improved' method of constructing a cable sling consisting in the use of two groups of endless units, the units of the respective groups being equal in numbers, with the units of one group having a lay opposite to those ofthe other'group, the units of each group being pretwisted in an opposite direction to their lays and given a predetermined spiral pitch, leaving a loop at each end of each unit, gathering the loops at each end to form the eyes ofthe sling, and then untwistin said units as they are being passed over an under each other in a clockwise and anti-clockwise direction to form the finished product.

structing a cablesling, consisting .in the use of a plurality of endless units divided into Groups ofrigh't and left hand lays, said units eing pretwisted in opposite directions to their lay, and then untwisting saxil units as they are ybeing spirally interwove around a flexible core into a sling.

7. A new and improved method of constructing a cable sling, consisting in the use of 'a plurality of pretwisted endless units divided into groupsof right and left hand lays, said units being pretwisted in opposite directions to theirlay leaving loops at each end of each unit, gathering the loops at each end to form an eyeA for the sling, and untwisting said unitsy ofl the respective groups alternately as they Aare being passed over ,and under each other in opposite directions around a flexible core.

`8. A new and improved method of constructing a cable sling, consisting in the use of an eye at one end of the sling, then untwisting said units as they are being alternately extended helically in a clockwise and anti- Clockwise direction about the longitudinal axis of the sling.

9. A new and improved` method of constructing a -cable sling, consisting in the use of a plurality of pretwisted endless units having loopedy ends, folding said *units between their ends to form an eye at one end of the sling, untwisting said units as they are being extended helically in a clockwise and anticlockwise direction about the longitudinal axis of the sling, and finally gathering the looped ends of said units together to form an eye for the other end of the sling.

10. A new and improved method of constructing a cable sling, consisting in the use a finished product. and finally gathering said l looped ends together to form an eye at the other end of the sling. t

11. A new and improved method of constructing a cableA sling, consisting in the use of, a plurality of endless units divided into groups of right and left hand lays, the units of each group being pretwisted toward their ends from spaced points in their lengths, and in opposite directions from the lay of said units, leaving loops 'at the ends of each umt,

then folding the units of the respective groups between their endsto form an eye for one end of the sling by the intermediate portions of the units, then alternately passing the units of the respective groups in a clockwise and anti-clockwise direction about the longitudinal axis of the sling, untWist-ing each unit as it is thus Woven into the finished product, and finally gathering said loops .together to form an eye for the other end of the sling. i

12. A cable sling including a plurality of pretwisted endless units spirally interwoven in an untwisted condition so as to form a sling.

13. A cable sling including a plurality of pretwisted endless units equally divided into groups of right and left hand lays spirally interwoven in an untwisted condition to form a sling. A

14. A cable sling including a plurality of pretwisted endless units equally divided into groups of right and left hand lays spirally interwoven in an untwisted condition and arranged to present relatively sliding surfaces to each other at their points of intersection.

15.l A cable sling including a plurality of endless units pretwisted in opposite directions to their lay, and extended helically in a clockwise and anti-clockwise direction in an untwisted condition about the longitudinal axis of the sling.

1G. A cable sling including a plurality of endless units equally divided into groups of right and left hand lays, pretwisted in opposite directions to their lay and spirally interwoven in an untwisted condition so as to form the sling, and an eye for each end of the sling.

17. A. cable sling including a plurality of endless units equally divided into groups of right and leit hand lays, pretwisted in opposite-directions to their lay and having loops unit edly defining eyes 'lor the opposed ends of the sling, and said units being` spirally interwoven in an untwisted condition and in opposite directions to form a sling.

In testimony whereof I affix my signature.

JOSEPH MCCLINTOCK GARRIS. 

